TITLE: Mathematical places to visit
QUESTION [9 upvotes]: There are certain buildings and places on this planet where mathematicians can find delight because of the history, the art, the architecture, and for other reasons.  For example, the Alhambra with it's heavy use of geometric patterns.  Or, perhaps, going to the leaning tower of Pisa and playing games with calculating where it's shadow will be cast.  Clearly, there are many places with historical or related significance to those interested in mathematics.  I would enjoy hearing about some from people here -- in particular, I would love to hear about any places in the middle east.

REPLY [4 votes]: See the Mathematical Tourist column, by Ivars Peterson, at the MAA site, for a large number of suggestions.